Switches are widely used for switching on and switching off electrical appliances. An example of such switches is an interlock switch. The interlock switch is commonly used for switching between two electrical circuits. For instance, a refrigerator usually has an interlock switch mounted to a frame defining a refrigerating chamber. The refrigerating chamber typically has a lamp for providing illumination when a door that is hinged mounted to the frame is opened. A fan used for circulating cold air in the refrigerating chamber is temporarily switched off when the door is opened. The lamp is then switched off in tandem with the fan being switched on again when the door is closed. This ensures that the circuit of one of two devices, for example, the lamp and the fan is electrically closed at any one time.
Interlock switches are commonly used in refrigerators for the purpose of providing an interlocking function for switching the lamp and the fan when the door is either opened or closed. Conventional interlock switches for this purpose typically consist of two pairs of electrically isolated conductive terminals. One of the two pairs of conductive terminals is used for providing electrical power to the lamp. The other pair of conductive terminals is used for providing electrical power to the fan. The two pairs of conductive terminals are therefore used for providing electrical power to either the lamp or the fan at any one time.
Operationally, conventional interlock switches use conductive blades for electrically connecting and disconnecting each pair of conductive terminals. Each conductive blade is typically actuable between pairs of conductive terminals. The conductive terminals and blades usually make contact at electrical contact points formed on the conductive terminals and blades. The conductive blades are typically arranged so that during actuation of the conventional interlock switches, only one pair of conductive terminals is electricity coupled for supplying electrical power to either the lamp or the fan.
The conductive terminals and blades of conventional interlock switches are usually positioned in proximity to one another. However, due to the close proximity between the conductive terminals and blades, any undesired positional deviation of each of the conductive terminals or blades may cause unwanted contact between the conductive terminals and blades. The presence of any foreign conductive object found within the conventional interlock switches may also result in undesirable electrical shorting between the conductive terminals and blades.
Other conventional interlock switches consisting of two pairs of conductive terminals that are typically used in electrical appliances for providing a safety feature for the electrical appliances. The safety feature usually requires full operability of the conventional interlock switches before electrical power is supplied for activating the electrical appliances. Therefore, if the conventional interlock switches malfunction during actuation, no electrical power is supplied to the electrical appliances.
However, electrically conductive carbon compound may be formed on the exterior of the conductive terminals, blades or electrical contact points of the conventional interlock switches because of prolonged use. This may result in undesirable electrical shorting between the conductive terminals and blades, especially when the electrical contact points of the conductive terminals and blades are positioned intimately to each other.
There is therefore a need for an interlock switch that is able to eliminate unintended contacts between conductive components thereof for improving the reliability of the interlock switch.